package com.project.util.initUtils;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTCreator;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.DecodedJWT;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class JwtUtil {
    private static final long EXPIRE_TIME = 1000 * 60 * 500; //过期时间毫秒
    private static final String TOKEN_SECRET = "j181";//密锁

    /**
     * 创建token
     *
     * @param map 需要放入token的内容
     * @return token
     */
    public static String createToken(Map<String, String> map) {
        //过期时间
        Date date = new Date(System.currentTimeMillis() + EXPIRE_TIME);
        //私钥及加密算法
        Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET);
        //设置头信息
        HashMap<String, Object> header = new HashMap<>(2);
        header.put("typ", "JWT");
        header.put("alg", "HS256");
        //附带username和userID生成签名
//        String token= JWT.create().withHeader(header)
//                .withClaim("userName", userName)
//                .withExpiresAt(date).sign(algorithm);
        JWTCreator.Builder builder = JWT.create().withHeader(header);
        for (String key : map.keySet()) {
            builder.withClaim(key, map.get(key));
        }
        return builder.withExpiresAt(date).sign(algorithm);
    }


    /**
     * 认证
     *
     * @param token 认真token,数组为token中存在的key
     * @return key对应的值，如果认证失败返回null
     */
    public static Map<String, String> verifierJwt(String token, String... strings) {
        Map<String, String> map = new HashMap<>();
        //私钥及加密算法
        Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET);
//       String userName="";
        JWTVerifier verifier = JWT.require(algorithm).build();
        try {
            DecodedJWT jwt = verifier.verify(token);
            for (String key : strings) {
                map.put(key, jwt.getClaim(key).asString());
            }
        } catch (Exception e) {
            return null;
        }
        return map;
    }
}
